Dead and dying Ceanothus sanguineus, C. velutinus, and C. integerrimus plants grown in a native plant nursery in Oregon for landscape restoration were reported in 2011. Plants were wilted with stem lesions above necrotic roots. Using selective media (Hansen et al. 2012), twelve similar Phytophthora isolates were obtained. DNA sequences...
A compact, low-cost, wireless gamma-ray spectrometer is a tool sought by a number of different organizations in the field of radiation detection. Such a device has applications in emergency response, battlefield assessment, and personal dosimetry. A prototype device fitting this description has been constructed in the Advanced Radiation Instrumentation Laboratory...
Early establishment of competing vegetation often presents an obstacle to the success of planted white spruce (Picea glauca (Moench) Voss) seedlings. We followed growth and development of white spruce and associated vegetation for up to 17 years in Alaska's boreal forests to quantify roles of overtopping plant cover in suppressing...
A genetic map populated with RAD and SSR markers was created from F1 progeny of a stem rust-susceptible and stem rust-resistant parent of perennial ryegrass (Lolium perenne). The map supplements a previous map of this population by having markers in common with several other Lolium spp. maps including EST-SSR anchor...
A compartmental modeling approach is presented to route nitrate retention along a cascade of stream reach sections. A process transfer function is used for transient storage equations with first-order reaction terms to represent nitrate uptake in the free stream and denitrification in the storage regions. In the context of a...
We determined the spatial pattern of dwarf mistletoe (Arceuthobium
spp.) associated with two different conifer hosts, white fir (Abies
concolor) and Jeffrey pine (Pinus jeffreyi), in forests around the Lake
Tahoe Basin and at the Teakettle Experimental Forest, both located in the
Sierra Nevada. We also examined a number of...
We determined the incidence of pathogens and insects across mixed-conifer stands in the Sierra San Pedro
Martir (SSPM) of northern Baja, Mexico, to assess the role of pests in a pristine forest ecosystem. We also determined
the spatial distribution of the two most common pests, mistletoe, Phoradendron pauciflorum Torrey, and...
Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled...
Aerobic oxidation is important in the cycling of methane in the sediments of Lake Washington. About half of the methane flux from depth is oxidized to CO, in the upper 0.7 cm of the sediments and the remainder escapes into the water column. In terms of the total carbon budget...
Soils are globally significant sources and sinks of
atmospheric CO₂. Increasing the resolution of soil carbon
turnover estimates is important for predicting the response of
soil carbon cycling to environmental change. We show that
soil carbon turnover times can be more finely resolved using
a dual isotope label like the...